From patchwork Tue Jan 17 03:49:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baoquan He X-Patchwork-Id: 13104156 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 225C7C6379F for ; Tue, 17 Jan 2023 03:51:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=u8MCaQNNviVGw3tZkmTtICddVImZEgiXiC5XmfEREwo=; b=mG0uvP9CCHDJ2t HjbOV92fgTVXjqVahzxwXkyqOENEsshcQPCFfYbq4sP3k2kX82ewJ1tEYYF9x9sEtQqld39YvHngz IsipVqTZVvQzedXSx0ydChnFiGGKhmPU6ZM+zr9hslLZgz5e3sMFXqcZc1GPr5mdLFD0i2GShNQu6 8hKX9iFxyermJSLsh03b4sF+6MtJczVyijKm24+E3HTJlsO282KDV4sr5Dzvl0XmZu68fEw9lEt1Y NsjmghoMeWCD0AigGRQh66ZU2fO5nHmiQtR1/mj75Nxm3mpXlckcR5PDE7YnkQqfvo8oMhJmjtYRK lKwbCYTElqwY+yui/oNw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pHcz5-00Co1E-PV; Tue, 17 Jan 2023 03:50:03 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pHcyo-00Cnuw-BM for linux-arm-kernel@lists.infradead.org; Tue, 17 Jan 2023 03:49:47 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673927385; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Tq8BWi7KIMXK19sTfFEOHzGCHbw3j+yt4nwzlz7Cvoc=; b=R2IDsVO0QVb5FAOSAuFTOOU5tQbhVfj9IaXYoNKAmDpjRMoomwAC23VnJpjkwUe8UxG+GR B6a2JtmhXJA1kChv5hm44NjTX3hGk9BeW4bpj3zO4CzncNQbI9Qo4W5gcjxCcM95fWRKzm KesEIsmbHD9rqD5ohJ1RBPrO9946yy8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-487-upN5m9UrNDW622U8L_BpjQ-1; Mon, 16 Jan 2023 22:49:41 -0500 X-MC-Unique: upN5m9UrNDW622U8L_BpjQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CA8EA101A52E; Tue, 17 Jan 2023 03:49:40 +0000 (UTC) Received: from fedora.redhat.com (ovpn-12-229.pek2.redhat.com [10.72.12.229]) by smtp.corp.redhat.com (Postfix) with ESMTP id D146A14171B8; Tue, 17 Jan 2023 03:49:35 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will@kernel.org, thunder.leizhen@huawei.com, John.p.donnelly@oracle.com, wangkefeng.wang@huawei.com, Baoquan He Subject: [PATCH 2/2] arm64/kdump: add code comments for crashkernel reservation cases Date: Tue, 17 Jan 2023 11:49:21 +0800 Message-Id: <20230117034921.185150-3-bhe@redhat.com> In-Reply-To: <20230117034921.185150-1-bhe@redhat.com> References: <20230117034921.185150-1-bhe@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230116_194946_491595_7B85B9DD X-CRM114-Status: GOOD ( 13.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This will help understand codes on crashkernel reservations on arm64. Signed-off-by: Baoquan He --- arch/arm64/mm/init.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 26a05af2bfa8..f88ad17cb20d 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -177,6 +177,10 @@ static void __init reserve_crashkernel(void) crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, search_base, crash_max); if (!crash_base) { + /* + * For crashkernel=size[KMG]@offset[KMG], print out failure + * message if can't reserve the specified region. + */ if (fixed_base) { pr_warn("cannot reserve crashkernel region [0x%llx-0x%llx]\n", search_base, crash_max); @@ -188,6 +192,11 @@ static void __init reserve_crashkernel(void) * high memory, the minimum required low memory will be * reserved later. */ + /* + * For crashkernel=size[KMG], if the first attempt was for + * low memory, fall back to high memory, the minimum required + * low memory will be reserved later. + */ if (!high && crash_max == CRASH_ADDR_LOW_MAX) { crash_max = CRASH_ADDR_HIGH_MAX; search_base = CRASH_ADDR_LOW_MAX; @@ -195,6 +204,10 @@ static void __init reserve_crashkernel(void) goto retry; } + /* + * For crashkernel=size[KMG],high, if the first attempt was for + * high memory, fall back to low memory. + */ if (high && (crash_max == CRASH_ADDR_HIGH_MAX)) { crash_max = CRASH_ADDR_LOW_MAX; search_base = 0;